This invention relates to a hardness measuring probe with which the hardness of an object to be measured can be continuously and quickly measured by a simple operation.
Recently, extensive use has been made of an endoscope with which the irregularity of an affected part or the state of a tumor can be observed with an elongated inserted part introduced into a body or cavity or, as required, a therapeutic treatment can be made by using a forceps.
However, with an endoscope, the hardness of a tumor or the state of a node in an affected part can not be detected.
Further, the hardness of the tumor in the above mentioned affected part is different depending on the kind and growth stage. Therefore, if such hardness is detected and is made data for the diagnosis, the diagnosis will be able to be made more accurate.
Heretofore, it has been known to use a pressure-sensitive element at the tip of a flexible bar-shaped member which can be advanced and retreated within a tubular member such as a forceps channel in an endoscope as is disclosed in the Gazette of the Japanese utility Model Publication No. 18371/1975.
In cases where the detection of variations in hardness of a normal part and an affected part abiut an object position depends on the degree of pressing, the measurement results, even in the same place will fluctuate. Also, there has been difficulty in repeating the contacting and separating operations. Further, there has been a defect that, unless the measuring intervals are carefully set, the necessary position will not be able to be measured.
In order to prevent the fluctuation of the measured result, it has been known to provide the pressure-sensitive element with a seat body of such shape as opens in the form of a cone to enclose the bar-shaped member to keep the force pressing the pressure-sensitive element constant in measuring the hardness as is disclosed in the Gazette of Japanese Utility Model Publication No. 18372/1975. In this example, if the surface to be measured is substantially flat, there will be no problem but, if it is a recessed surface of the irregularity, the surroundseat body will contact a projecting surface adjacent to the recessed surface, the pressure-sensitive element part will not be able to well contact the recessed surface and the measuring precision will reduce.
Further, unless the surrounding seat body is pressed against the surface to be measured in a uniformly contacting direction, the measured value will greatly fluctuate and the measuring direction will be restricted. Therefore, places where the pressure-sensitive element can be used are limited.
There is substantially the same problem even where a hood is provided on the outer periphery of the tip part of an endoscope as is disclosed in the Gazette of Japanese Utility Model Publication No. 18373/1975.
It has also been known to have a distortion gauge contained in a container fitted to the tip of an endoscope or the like with a presser fixed on the base side of the distortion gauge and is partly projected on the tip side out of the container as is disclosed in the Gazette of Japanese Patent Laid Open No. 98378/1977. Even in this example, there is substantially the same problem that, in such measuring position in which the surface of the container around the presser will contact a projection in the case of the measurement, it will be difficult to precisely measure the hardness of a recessed surface adjacent to the projection.
Also, in the prior art example disclosed in the Gazette of Japanese Utility Model Laid Open No. 51235/1980, unless the object position can be held, the hardness will not be able to be measured and therefore use will be greatly limited.
Further, it has been known to extend two flexible narrow plate-shaped members out in parallel with each other with distortion gauges fitted on each. In addition, one member is curved at the tip by 90 degrees and is passed through a slot-shaped incision formed at the tip of the other member so as to partly project at the curved tip as is disclosed in U.S. Pat. No. 4,132,224. In this example, in case the curved tip vertically presses an object position, the hardness will be able to be measured at a high precision but, for an object which can not be pressed from the vertical direction, the function will not be developed.
Further, this example is not well adapted to the measurement of the hardness within a living body as judged from the fact that, in this example, the surface vertical to the direction in which the plate members are parallelly expanded out can be measured and therefore the hardness of the surface of an affected part forward in the inserting direction which can be well observed with an ordinary straight sight type endoscope can not be observed.
Further, the above mentioned problems derive from the basic structures and are hard to simply solve.
Each of the above described prior art examples has problems in cases of measuring the hardness of an affected part or the like within a body cavity inflated with air. That is, if the atmospheric pressure around an affected part varies during the measurement, the atmospheric pressure acting on the pressure-sensitive element will appear as varied in the measured result and the pressure pressing the affected part will appear as varied in the measured result. Thus, much time will be required to precisely measure the hardness around the object position. Further, there is a problem that, in the measurement for a long time, the operation will be so difficult that the measurement will be likely to become rough.